JPH0480934B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to polyols for rigid foams, and more particularly to a method for producing aromatic polyester polyols from polyethylene terephthalate residues. That is, the present invention involves reacting a polyethylene terephthalate residue having ester functionalities with an alkylene oxide in the presence of a basic catalyst,
A method of producing an aromatic polyol having ester functionality is provided, the method comprising producing an aromatic polyester polyol. These polyols are used in the production of rigid polyurethane foams to impart improved fire resistance to the foams. It is known to produce foams from polyurethanes by reacting polyisocyanates, polyols and blowing agents such as halogenated hydrocarbons, water or both in the presence of catalysts.
One particular area of polyurethane technology is based on rigid polyurethane foams. This technology encompasses a wide variety of polyols that are useful as one of the main components when making polyurethanes, such as polyurethane foams. As a specific example, U.S. Pat. No. 2,965,615 discloses copolymers of alkenyl-substituted aromatic compounds such as styrene and ethylenically unsaturated monohydric alcohols such as allyl alcohol as resinous polyols useful in urethane production. and also disclose alkoxylation reaction products of the above copolymers as useful polyol sources. Further, US Pat. No. 4,094,828 discloses a method in which a polyol composition consisting of a copolymer of allyl alcohol and styrene and a polyether polyol provides a rigid polyurethane foam with outstanding dimensional stability and heat distortion properties. Aminopolyols can be modified with epoxy resins and alkylene oxides according to the invention disclosed in US Pat. No. 4,309,532. These modified polyols provide rigid polyurethane foams that have higher heat distortion temperatures and better low temperature properties than the foams obtained using less modified polyols in this manner. Rigid foams generally have good thermal insulation properties and are therefore desirable for building insulation. As with all construction materials, it is desirable to provide a rigid foam that is as fire resistant as possible. One approach to this goal is to modify the polyol. Polyisocyanurate foams are considered fire resistant and produce less smoke when burned. However, polyisocyanurate foams tend to be brittle and brittle. Although various types of polyols have been proposed to reduce the brittleness of the foam, deterioration of the fire and smoke properties of polyisocyanurate foams often occurs. Thus, a delicate balance exists between the amount and type of polyol added to polyisocyanurate foam formulations to maintain maximum flame and smoke resistance while simultaneously improving foam brittleness. U.S. Patent No. 4039487 and
Although each of No. 4092276 has its drawbacks,
Attempts to strike this delicate balance are disclosed. It is known to incorporate waste polyalkylene terephthalates, such as polyethylene terephthalate (PET), into polyurethanes. For example, U.S. Pat. No. 4,048,104 discloses that polyisocyanate prepolymers for making polyurethanes can be prepared by combining an organic polyisocyanate and a polyol that is a hydroxyl-terminated aged product of a waste polyalkylene terephthalate polymer and an organic polyol. Regarding. A polyol component that is a polyalkylene terephthalate residue or waste aging product that is aged with an organic polyol is also described in US Pat. No. 4,223,068. Another embodiment in which terephthalic acid residue is used is disclosed in U.S. Pat. No. 4,246,365.
The outline is described in the patent No.
Polyurethanes are produced from polyesters containing at least two hydroxyl groups and terephthalic acid residues. The solution proposed in US Pat. No. 4,237,238 is
It is more closely related to the compounds of the present invention. In this patent, a polyol mixture is produced by transesterifying the production residue of dimethyl terephthalate with a glycol. This polyol mixture is then used to produce polyisocyanurate foams that have a high degree of fire resistance along with low smoke emission, low foam brittleness, and high pressure shrinkage. A method for producing such a polyol mixture (from ethylene glycol and dimethyl phthalate esterified oxidate residue) is described in US Pat. No. 3,647,759. JM
Hughes) and John Clinton
Clinton described other foams made from the polyols of U.S. Pat. ing. Other types of polyisocyanurate foams employ polyol mixtures using both amide diols and primary hydroxyl polyols, resulting in foams with high heats of reaction; It is particularly suitable for the production of laminates of polyisocyanurate foam. There continues to be a need for rigid polyurethane foams that have high flame resistance. Part of the problem with the polyol of U.S. Pat. No. 3,647,759 is that the resulting foam is poorly coexistent with trichlorofluoromethane, the gas trapped in the closed-cell rigid foam, which is the source of the foam's excellent insulating properties. It is a lack of gender. The present invention relates to a method for producing aromatic polyols having ester and hydroxyl functional groups for the production of rigid foams, wherein such aromatic polyols having ester functional groups are prepared from polyethylene terephthalate residues having ester functional groups ( The aromatic polyester polyol is produced by reacting the residue) with alkylene oxide in the presence of a basic catalyst to produce an aromatic polyester polyol. It has generally been found that rigid polyurethane foams with improved fire resistance can be made using mixtures of aromatic aminopolyols and the aromatic polyols of the present invention. In addition, such polyol mixtures can coexist with trichlorofluoromethane blowing agents. A novel aromatic ester polyol is produced using PET residue. This may be waste or waste residue from the production of polyethylene terephthalate and the like. This residue consists of the following parts, namely must contain a compound with This reaction yields a mixture of aromatic polyols with ester functionality. In fact, PET residue is a preferred feedstock for the present invention. These residues may contain hydroxyl groups. like this
One of the PET residue streams is described in the Examples.
What is important is that a cheap raw material for the terephthalic acid moiety can be obtained. A second class of reactants in the synthesis of the compounds of this invention includes alkylene oxides. In fact, alkylene oxides work effectively. These compounds have the following structure:

It has the formula: (wherein R represents an alkyl group, preferably an alkyl group having 1 to 4 carbon atoms). Simpler alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide are preferred, with propylene oxide being particularly preferred. Mixtures of oxides are also useful. The proportion of alkylene oxide added should be sufficient to obtain the desired OH (hydroxyl) number. The saponification value of the PET residue is also considered as an equivalent unit for adjusting the alkylene oxide ratio. The equivalent of alkylene oxide is combined with the equivalent of the esterification site of the PET residue.
Particularly preferred are oxide mixtures, such as mixtures of ethylene oxide and propylene oxide. This reaction is catalyzed by a basic substance. Preferably, bases such as alkali metal or alkaline earth metal hydroxides or tertiary amines are used. Sodium hydroxide, potassium hydroxide, and
Tertiary aminoalkylphenols such as 2,4,6-tris-(N,N-dimethylaminomethyl)phenol, also known as DMP, are particularly preferred as catalysts. This catalyst is effective against residues.
It can be present in an amount of 0.1 to 10% by weight, preferably 0.5 to 3.5% by weight. The temperature of this reaction is about 100-200°C, preferably 120-160°C. Pressure is generally 1 to 40
bar, preferably in the range 1 to 10 bar.
The polyol has a molecular weight of 100 to 300, particularly preferably 140 to
It has a hydroxyl number in the range of 240. When these polyols are mixed with conventional polyols, foams are produced that have better fire resistance compared to foams made from conventional polyols alone. The polyols of the invention can also be used to produce polyisocyanurate foams with good fire resistance. The polyols of the present invention can coexist better with trichlorofluoromethane compared to polyols of the type disclosed in US Pat. No. 3,647,759. A conventional blowing agent, trichlorofluoromethane, sold under the trade name FREON R11B®, is the gas trapped in closed cell rigid foams that is responsible for the excellent thermal insulation properties of these foams. The polyol mixtures of the present invention can be used as the sole polyol component in polyurethane foam formulations or, preferably, as part of a blend of polyols. These polyols are
It may also be used in polyisocyanurate foams.
In general, the polyol mixtures of the present invention are useful as polyol extenders and can replace more expensive polyols to some extent. A second component of the total polyol mixture that has been found to be particularly useful in the production of rigid polyurethane foams has a hydroxyl number between 200 and 800.
It is a polyether polyol having usually,
The polyether polyol is 0 to 95% by weight of the total polyol mixture weight. Preferred polyether polyols of this type are the reaction products of polyfunctional active hydrogen initiators and propylene oxide, ethylene oxide or mixtures of propylene oxide and ethylene oxide. Most preferably, the multifunctional active hydrogen initiator has a functionality of 2 to 8. A wide variety of initiators can be alkoxylated to form useful polyether polyols. Thus, for example, polyfunctional amines of the following types, such as monoethanolamine, diethanolamine, triethanolamine, and polyfunctional alcohols, such as ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, glycerin, sorbitol, trimethylolpropane, sucrose. and other carbohydrates can be alkoxylated. Such amines or alcohols may be reacted with alkylene oxides such as ethylene oxide, propylene oxide or mixtures of both using techniques known to those skilled in the art. Thus, for example, the reaction of alkylene oxides with this type of initiator is described in U.S. Pat.
3000963. Such alkoxylation is substantially carried out in the presence of a basic catalyst and at a temperature sufficient to sustain the reaction. The desired hydroxyl number of the final polyol determines the amount of alkylene oxide used to react with the initiator. As mentioned above, polyether polyols useful herein have hydroxyl numbers ranging from about 200 to about 800. The reaction mixture is then neutralized to remove water and excess reactants from the polyol. This polyether polyol is
reacting the initiator with propylene oxide or ethylene oxide or in one or more steps by reacting the initiator first with propylene oxide and then with ethylene oxide or vice versa; So-called block polymer chains can be obtained or they can be prepared by reacting the initiator with a polypropylene oxide-ethylene oxide mixture all at once to obtain a random distribution of such alkylene oxides. Particularly preferred as a component of the second polyol are the nitrogen-containing polyether polyols described in US Pat. Nos. 3,297,597 and 4,137,265, which are incorporated herein by reference. These particularly preferred polyols are manufactured by Taxaco Chemical Company.
THANOL R-350-X and
It is commercially available as THANOLR-650-X polyols. These polyols are prepared by reacting 2 to 3 moles of propylene oxide with 1 mole of the Mannich reaction product of 1 mole of phenol or nonylphenol and 1 or 2 moles of diethanolamine. More preferably, the final polyol mixture is
0 to 95% by weight of the polyether polyol and
It consists of 100-5% by weight of aromatic polyester polyol. Although the aromatic polyols of the present invention can be used alone, 30 to 70%
Preferably, it is present in % by weight. Polyol mixtures often have a total hydroxyl number ranging from about 200 to about 600. A preferred range is a hydroxyl number of 300-500. Any aromatic polyisocyanate can be used in the process of the invention. Representative aromatic polyisocyanates include m-phenylene diisocyanate, p-phenylene diisocyanate, polymethylene polyphenyl isocyanate,
Examples include 2,4-toluene diisocyanate, 2,6-tolylene diisocyanate, dianisidine diisocyanate, bitylylene diisocyanate, naphthalene-1,4-diisocyanate, diphenylene-4,4'-diisocyanate, and aliphatic-aromatic diisocyanates. Examples include xylylene-1,4-diisocyanate, xylylene-1,4-diisocyanate,
1,2-diisocyanate, xylylene-1,3
-diisocyanate, bis(4-isocyanatophenyl)methane, bis(3-methyl-4-isocyanatophenyl)methane, 4,4'-diphenylpropane diisocyanate, and the like. A highly preferred aromatic polyisocyanate for use in the practice of this invention is a methylene crosslinked polyphenyl polyisocyanate mixture having a functionality of about 2 to about 4. These latter isocyanate compounds, generally prepared by phosgenation of the corresponding methylene-bridged polyphenyl polyamines, are prepared by reacting formaldehyde and a primary aromatic amine such as aniline with hydrochloric acid and/or other It is usually produced by reaction in the presence of an acidic catalyst. Known methods for making methylene-crosslinked polyphenylpolyamines and corresponding methylene-crosslinked polyphenylpolyisocyanates are well known in the literature and in numerous patents, such as U.S. Pat.
It is described in No. 2683730, No. 2950263, No. 3012008, No. 3344162, and No. 3362979. The most preferred methylene-bridged polyphenyl polyisocyanate mixtures used herein are from about 20 to
It contains about 100% by weight methylene diphenyl diisocyanate isomers, the remainder being polymethylene polyphenyl polyisocyanate having high functionality and high molecular weight. Typical of these are polyphenyl polyisocyanate mixtures containing from about 20 to 100% by weight of a mixture of methylene diphenyl diisocyanate isomers, in which 20 to about 95% by weight are 4,4'-isomers. and the remainder is a high molecular weight polymethylene polyisocyanate having an average functionality of from about 2.1 to about 3.5. This isocyanate mixture is a known commercial material and can be prepared by the method described in U.S. Pat. No. 3,362,979, issued to Floyd E. Bentley on January 9, 1968. Other known additives are required for the production of rigid polyurethane foams in the practice of this invention. One such component is a blowing agent.
Some specific examples of such materials include trichloromonofluoromethane, dichlorodifluoromethane, dichloromonofluoromethane, 1,1-dichloro-1-fluoroethane, 1,1-difluoro-
Examples include 1,2,2-trichloroethane and chloropentafluoroethane. Other useful blowing agents include low boiling hydrocarbons such as butane, pentane, hexane, cyclohexane (see, eg, US Pat. No. 3,072,582). The polyols of the present invention can coexist well with fluorocarbon blowing agents, unlike some of the prior art polyols, which are also made from dimethyl terephthalate (DMT) residues. A surfactant, better known as silicone oil, is added to act as a foam stabilizer. Some typical materials are listed under the trade name
Commercially available as SF-1109, L-520, L-521 and DC-193. These are generally polysiloxane polyoxyalkylene block copolymers as described, for example, in US Pat. Nos. 2,834,748, 2,917,480 and 2,846,458. If additional flame retardant properties are required for polyurethane foams, two types of flame retardants are available. That is, they are those that are incorporated by mere mechanical mixing and those that are chemically bonded to the polymer chain. A typical example of the first type is
Tris(chloroethyl) phosphate, tris(2,3-dibromopropyl) phosphate, diammonium phosphate, various halogenated compounds and antimony oxide. Representative examples of chemically bonded types are chloreneditsic acid derivatives and various phosphorus-containing polyols. Catalysts that can be used to produce the foams of the invention are known. There are two common catalysts: tertiary amines and organometallic compounds. Specific examples of suitable tertiary amines used separately or in combination include N-alkylmorpholine, N-alkylalkanolamine, N, where the alkyl group is methyl, ethyl, propyl, butyl, etc. Examples include N-dialkylcyclohexylamine and alkylamine. Specific examples of specific tertiary amine catalysts used in the present invention include triethylenediamine, tetramethylethylenediamine, triethylamine, tripropylamine, tributylamine, triamylamine, pyridine, quinoline, dimethylpiperazine,
Dimethylhexahydroaniline, piperazine, N
-Ethylmorpholine, 2-methylpiperazine, dimethylaniline, nicotine, dimethylaminoethanol, tetramethylpropanediamine, methyltriethylenediamine, and the like. Organometallic compounds useful as catalysts include bismuth,
Lead, tin, titanium, iron, antimony, uranium, cadmium, cobalt, thorium, aluminum,
Mercury, zinc, nickel, cerium, molybdenum,
Examples include organometallic compounds of metals such as vanadium, copper, manganese, and zirconium. Some specific examples of these metal catalysts include bismuth nitrate, lead 2-ethylhexoate, lead benzoate, lead oleate, dibutyltin(tin) dilaurate, tributyltin, butyltin trichloride, tin chloride, octene. stannous acid, tin oleate,
Examples include dibutyltin (tin) di(2-ethylhexoate), ferric chloride, antimony trichloride, antimony glycolate, and tin glycolate. It should be noted that the polyols of the present invention have a significant metal content, especially antimony. Furthermore, when using the polyol of the present invention,
It should be noted that the cream time of the foam is reduced. The selection of individual catalysts and the ratios used in polyurethane reactions are well known to those skilled in the art, and amines and organometallic compounds are often used together in polyurethane reactions. The rigid polyurethane foams produced here can also be produced in one step by reacting all the components together (one-shot method), or the rigid foams can be produced in a so-called "quasiprepolymer method". It can be manufactured by a method. According to this method, a portion of the polyol component is reacted with a polyisocyanate component in the absence of a catalyst in a ratio such that the free isocyanate groups of the reaction product are from about 20 to about 40% of the polyol. let To produce the foam, the remainder of the polyol is added and the two components are allowed to react in the presence of a non-solvent and other suitable additives such as blowing agents, foam stabilizers, flame retardants, etc. Blowing agents, cell stabilizers, flame retardants, etc. can be added to either the prepolymer or the residual polyol, or both, before mixing the above components, thereby resulting in a rigid polyurethane foam at the end of the reaction. . In a preferred embodiment, the amount of polyol mixture is used such that isocyanate groups are present in the foam in at least an equivalent amount, preferably in slight excess, compared to free hydroxyl groups. Preferably, the above components are added in an amount of about 1.05 molar equivalents of hydroxyl groups.
~8.0 molar equivalents of isocyanate groups. The invention will be further described with reference to the following specific examples, which are intended to be illustrative and not to limit the scope of the invention. The synthesis of the polyols of the invention is presented along with examples showing how these polyols can be used to produce foams with improved properties. A. Production of aromatic polyester polyols PET distillation residue stream In all examples,
PET waste stream has the following characteristics: Hydroxyl number 236 Acid number 3 Saponification number 306 Ash content (%) 0.6 Antimony (%) 0.75 Phosphorus (ppm) 564 Iron (ppm) 333 Cobalt (ppm) 165 Zinc (ppm) 53 Calcium (ppm) 19 Magnesium (ppm) 7 Manganese (ppm) 6 This raw material is a hard putty-like or caulk-like solid, which is a typical PET residue. The aromatic polyester polyols in all Examples were produced according to the following method. Solid PET still residue stream and flaky potassium hydroxide (3.5% relative to PET) or 2,4,
6-Tris-(N,N-dimethylaminomethyl)
Phenol (DMP-30; 0.5 to PET
1.1%) catalyst was replaced with clean dry nitrogen
It was filled into a 1500ml stirring vessel. The vessel was purged with nitrogen, filled with nitrogen, heated to the desired temperature and then propylene oxide (PO) and/or ethylene oxide (EO) were added at several intervals at a maximum of 5.14 bar. After all the alkylene oxide was added, the reaction mixture was aged for about 1 hour at the indicated temperature. Then heat the whole thing to 90℃
and evacuated. In experiments using KOH as a catalyst, neutralization was achieved by stirring with a Britesorb 90 (synthetic magnesium silicate)/water slurry. The volatiles and water were removed at 90° C./5 mm, then the product was filtered hot and placed in a container. DMP
In experiments using the -30 catalyst, the neutralization and filtration steps were omitted. The product was a free flowing opaque liquid. Detailed reaction conditions and product analysis are listed below.

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[Table] B. Production of Foam The ingredients were mixed at 2700 rpm, poured into an open mold, and foamed. Physical properties were measured after the foams were left at room temperature for at least 3 days. The formulation and physical properties of the selected cases are listed below.

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It can be seen that the polyol mixtures of the present invention produce excellent polyurethane and polyisocyanurate foams. Additionally, the polyol mixtures of the present invention impart greater fire resistance to rigid foams compared to other polyols. For example, forms of formulations B, C, D and E, formulation G,
Comparing the forms H, I and J with the forms A and F, respectively, it is clear that the foams made with the polyol mixture of the present invention are superior to the foams made with the conventional polyols (A and F), which do not have the contribution of the present invention. ) are understood to digest more quickly and retain more weight. Many variations are possible in the polyols of the invention without departing from the spirit and scope of the invention. For example, it will be found that polyol mixtures made from certain combinations of PET residues and alkylene oxides, or made at certain temperatures or pressures, may have advantages and optimal properties.

Claims (1)

[Claims] 1. An aromatic polyester polyol having an ester functional group, characterized in that an aromatic polyester polyol is produced by reacting a polyethylene terephthalate residue having an ester functional group with an alkylene oxide in the presence of a basic catalyst. A method of producing polyols. 2. The method according to claim 1, wherein the alkylene oxide is ethylene oxide or propylene oxide. 3. The method according to claim 1, wherein the basic catalyst is an alkali or alkaline earth metal hydroxide or a tertiary amine. 4. The method according to claim 3, wherein the basic catalyst is sodium hydroxide, potassium hydroxide or tertiary aminoalkylphenol.